Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New way of removing excess nitrogen from the environment

02.11.2010
Denitrifying bioreactors subject of workshop, special scientific journal issue

Excess nitrogen from agricultural and urban lands is contaminating groundwater, streams, lakes and estuaries, where it causes harmful algal blooms and contributes to fish kills.

Cost-effective approaches to removing this nitrogen from croplands and urban stormwater runoff before it reaches sensitive water bodies have been elusive.

But simple and inexpensive technologies are on the horizon. A recent scientific workshop on denitrification brought together ecologists, engineers and policy experts to find answers.

Denitrification is a biological process carried out by soil and aquatic microorganisms, in which forms of reactive nitrogen are converted to unreactive and harmless dinitrogen gas.

Findings from the workshop, held in May, 2009, at the University of Rhode Island, are published in the November, 2010, special issue of the scientific journal Ecological Engineering.

The workshop was sponsored by the National Science Foundation (NSF)'s Denitrification Research Coordination Network (RCN), established to enhance collaboration among researchers investigating denitrification.

"This special issue of Ecological Engineering, with its focus on managing denitrification in human-dominated landscapes, highlights our need to understand Earth's microorganisms and their processes," says Matt Kane, program director in NSF's Division of Environmental Biology, which funded the RCN and the workshop.

"The RCN brought together an international and interdisciplinary group of scientists and engineers to synthesize the knowledge necessary to provide pure water for generations to come."

At the workshop, more than 40 participants combined their expertise to address the goal of using ecological principles in engineering design to control nitrogen pollution.

One workshop goal was to evaluate a new and relatively inexpensive way to treat wastewater and drainage from agricultural lands using "denitrifying bioreactors."

These bioreactors use common waste products, such as wood chips, to provide a food source for naturally occurring microorganisms. The microbes convert dissolved nitrogen into harmless nitrogen gas, which is then released to the atmosphere.

Research results in Ecological Engineering are reported from New Zealand, Canada and several locations in the United States.

All confirm that denitrifying bioreactors may be used in many settings, and operate well in a range of temperatures.

The systems have been successful in the cleanup of domestic effluent from small townships, septic tank systems and wastes from dairy farms, says Louis Schipper of the University of Waikato, New Zealand, author of the lead paper in the journal.

"Denitrifying bioreactors have been integrated into agricultural fields," adds Eric Davidson of The Woods Hole Research Center in Falmouth, Mass., and co-author of the journal's lead paper.

"Underground drainage pipes there remove excess water that contains excess nitrogen. By intercepting some of this drainage water, direct inputs of nitrate to surface water can be reduced."

The largest bioreactor tested, by Schipper and colleagues Stewart Cameron and Soren Warneke at the University of Waikato, is 200 meters long by five meters wide by two meters deep. It treats effluent from greenhouse-grown tomatoes.

Research led by Will Robertson of the University of Waterloo found that bioreactors may operate for more than a decade without replacement of wood chips or substantive maintenance.

Similar longevity was confirmed in research in Iowa by Tom Moorman of the USDA-Agricultural Research Service.

Studies by D.Q. Kellogg and Art Gold of the University of Rhode Island demonstrate that recent advances in geospatial data--such as computer-based maps of geologic and land-use patterns--provide a decision-support tool for local regulatory and planning agencies.

These advances, Kellogg and Gold say, will help reduce nitrate-loading to downstream waters.

A study conducted at the University of California at Davis by Harold Leverenz and reported in the journal showed that plants may be grown on the surface of denitrifying bioreactors, providing biodiversity benefits.

"Research presented in this special issue of Ecological Engineering goes a long way toward applying a scientific understanding of the biological processes of denitrification to the engineering challenges of denitrifying bioreactors," says Davidson.

"The resulting guidelines and principles for denitrifying bioreactor design and operation are an additional option in the land manager's tool box."

Cheryl Dybas | EurekAlert!
Further information:
http://www.nsf.gov

More articles from Ecology, The Environment and Conservation:

nachricht Safeguarding sustainability through forest certification mapping
27.06.2017 | International Institute for Applied Systems Analysis (IIASA)

nachricht Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>